Authentication in information and communication security systems relates to establishing that a user or system is who or what the user or system purports to be. Using a secret password or code to control user access to a computer system is a simple example of authenticating a user. Passwords or codes can be copied, divulged, or guessed by imposters, attackers, or hackers. Requiring the presence of a physical item for authentication can assist in mitigating this security risk. However, physical items can be duplicated or otherwise mechanically circumvented.